VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 '31 use of electric fuel pump

When I first got the engine running on my '31 3 years ago, we installed a 6V inline fuel pump (from FS) amidships, removed the guts from the malfunctioning original pump, and all seemed to work fine. I since then have been restoring the car, had gas tank and lines all out, etc, and have now installed a rebuilt original fuel pump. I am ready to reinstall tank and fuel line and looking for advice on what to do about the inline 6V electric pump, i.e. can it be left in place and used only if needed, will the original diaphragm type pump work if pump is left in line (will gas be able to be drawn through pump),etc. Any advice/knowledge out there?

I would think that the electric pump may cause a restricton on the flow. If you dont want to replace all of the line with a new one then maybe a small spool piece could be added in its place. You could also install an in line filter in its location .

The use of an electrical fuel pump is not a good idea. They can lead to problems of safety if any rubber lines are used. Primarily a fire hazard. Our old Chevies run fine utilizing the mechanical pump.

I agree and the same goes for the 4-cylinders.

I know of a 32 Phaeton which burned up due to an electric fuel pump....get rid of it, you are just asking for problems.

I have put lots of electric fuel pumps on, one customer with a number of old cars liked them for filling the carb after sitting for a while, made starting quicker. He never had a problem with the pump pulling through the electric pump.

OK, guess it will have to go. I have a copper line full length, should it be steel? Also, if I use the old copper line, I will need to add a coupling where electric fuel pump was cut in (about 6"-8" of line was removed). Is there a standard coupling/solution used for splicing?

I would not use copper. It is subject to crack. I would use steel. In industry we used copper plated steel. Parts housed will carry steel for brake lines. Just my suggestion.

I have the same problem with my 31, As an electrical fuel pump was add and pumped thru the old engine pump. I am thinking of using a by pass line and valve. Just for the purpose of fuel pump failure on the mechanical one. I like the reply about pumping fuel up for easier starting after sitting.

Electrical fuel pumps are not all bad. If they are wired in right to start with. A blow-able fuss is most needed. Not one that will reset when it cools down. Plus wired on the key switch, it's off when everything else is off. Just about every new auto built in the last 20 years has an electrical fuel pump.
See you everett

Hello Gunsmoke,
I'm trying to figure if the mechanical fuel pump were to fail, would an electrical pump within the system be able to force fuel beyond the mechanical pump? If it can, you may not become broke down. On the other hand, having a spare mechanical fuel pump and gasket in the emergency kit could get you going again. It seems you have some options, but the key is whether or not a failed pump will bypass or not, I don't know.

I have been using NiCopp tubing as of late. It is Nichol and Copper. Does not crack or break and is DOT approved. Bends for forming easily and also Flares fine like copper. Google it. Al W. BTW, Mechanical Pumps on our cars do not just suddenly quit. They usually start a slight drip when the Diaphragm gets worn out. So, an electric inline pump is really unnecessary.

Ok so I plan to use the original pump only, will keep the electric one in the trunk for down the road if needed. Now the question is routing of the new fuel line. Assuming I can get a NiComm or similar flexible line, where does it go and is it one piece? Does it for example go along upper inside part of steel side member, behind battery box, behind cross-member brace, and behind rear shock absorber to gas tank? Does it have any allowance for expansion or flexing, how is it held in place to avoid rattling around? Have to ask as mine had been replaced with copper and did not look very carefully installed (surprise!)

I cant speek to a 31 but the 32 has steel clamps that bolt to the frame with 1/4 20 x5/8 inch stove bolts and square nuts. I think the line is one piece until the fuel pump.I need to replace mine the one I removed was copper. I think steel or nickel /copper would be the best choice .copper can work harden and crack.On my sedan I used ruberized clamps in stead of the original steel clamps. Not oem but reduced vibration noise.

The original '31 and '32 fuel lines were one piece plated steel from tank to fuel pump and another single piece from pump to carburetor. The line from tank to fuel pump is held tight by several clamps (seem to remember 5 but that could be increased or decreased by one). Rubber coated clamps can give more movement and therefore noise.

Chipper, can you let me know where it was placed, I don't see many holes for clamps, but have not looked fully. Does it go in back of rear shock, or curl out around it? I assume putting it in a somewhat protected location is preferable. Finally, install from rear toward front or from front?

Oh Gosh!
You will get me to look. It has been too many years since I fabricated and installed a replacement gas line. Unfortunately the original line that I used as a pattern and replacement are on a car 120 miles away. Was just there yesterday. Will not get back for another week or two. Maybe I can find a picture or two. Don't hold your breath. I have two '31 frames here without gas lines maybe I can look at one of them and jog my memory.

It does install from the back.

My car has the original line. I'll take a few photos over the weekend and post them. Al W.

Hey Al can you also note the location of each clip? Then we can get Bill B to add it to his website.

Sure, will do!

I have an original fuel line out in my shop... Maybe I can take a photo of it.... but it wont' help too much since the bends need to be within 1/2" to 1" of the correct location.

Yes, I'll be happy to add anything to the web site if you send me a copy.

One thought.... in 1985 when I replaced my first gas line, I used TWO sections of fuel line -- each about 8 feet long. Therefore ended up with a connection in the middle of the car... no big deal, really.

But when I did the Landau last year, I got a full length section from TFS and added the connectors to the two ends.

--Bill

Starting at the Gas Tank.
It runs along the ledge of the frame held in place by an all metal clamp.
Then it dips under/around the spring perch.
Running again along the lower rail it is held in place by another all Metal clamp. See the square nut just before the Battery Box.
Here's another view of the Square Bolts location to rear of Battery Box.
Finally up at the rear of the engine/Trans Cross member held in place once again by an all metal clamp.

Great photos Al. A question and a puzzle. First the question, does it go in behind rear shock and if so, only gap I believe is near upper part of shock? What is puzzling me is why the line would dip down and around cross member bracket rather than continue along in straight line within frame rail protected from the elements. Is it possible your line is not original? Putting it behind this bracket would be a lot harder if using a one piece line, so I am wondering if a replacement line avoided this problem by going around the bracket as shown. Dawg has an "all original 32" wonder how his goes?

I just noticed in photo #3 there is a hole perfectly placed for the line to go threw the Spring Perch. I'll check my other car on Weds. which I know to be original. Al W.

Yes there is a hole but with the ferrules installed the line will not go through the hole. Besides the movement of the line will eventually wear a hole in the line. No the original routing for at least all the '31s I have owned go around the spring bracket. Maybe a few early ones might have possibly gone through the hole but not many if any.

Thanks for checking Al. The line on mine was copper, and I assume not original (my car is Canadian so who knows). The line had a neat horizontal sweeping curve (about an 8" arc) going past the spring perch, looked very deliberate and cleared the perch by an inch or so. By going horizontal and level with rest of line you avoid a low spot where water from condensation could collect and by staying clear you avoid rubbing etc, which might be a problem as shown in the pic. Can you have a look at area near rear shock and see how that is handled. Based on treatment around perch, I suspect they also swung out around the shock somehow, then back to frame and then out to tank,.